Dual path power transmissions have been suggested for a number of years. Initially, the dual path power transmissions were countershaft-type transmissions having two input clutches and separate countershafts having gears meshing with gears on a main or output shaft. The speed ratios through the transmission were alternated between one input clutch that transmitted engine torque to one of the countershafts and a second input clutch transmitting engine torque to another of the countershafts. The countershaft not currently transmitting torque could have the gear ratio thereon preselected for the next on-coming ratio, whether it be an upshift or a downshift. Likewise, when that ratio interchange had been accomplished, the first countershaft or the outgoing gear ratio countershaft would be preselected to the next oncoming ratio. The swapping of ratios for the ratio interchange is accomplished by the alternate action of the dual input clutches.
It has also been suggested to employ planetary transmissions in dual input clutch power transmissions. In dual input planetary transmissions, an input clutch is connected to a first planetary gearset either through a synchronizer or directly to one member. The reaction and output members are controlled by synchronizers, which complete the gear ratio or speed ratio through the individual gearsets. These dual input planetary-type transmissions employing synchronizers do not make use of the full range of ratios that are available in these planetary gearsets.